Percussive tool



Patented Jan. 29, 1.929.

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PATENT OFFICE.

ERNEST PENBERTI-IY, OF DETROIT, MICHIGAN, ASSIGNOR T0 CHI CAGO PNEUM ATIC TOOL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PERCUSSIVE TOOL.

Application filed January 28, 1924. Serial No. 689,082.

This invention relates to percussive drills of the fluid pressure type adapted for use in mining, quarrying and similar operations. Among the objects of the invention are to provide an improved construction for such tools adapting the same,'without change .or with very minor changes, for use in a variety of ways, for example, as a wet drill, as a dry drill, for shallow holes, for deep holes, for stoping, etc., to enable the operator to control both the percussive motor and the hole clearing means by the operation of a single valve, to permit the interchange of fluid tubes and rods whereby the same operative parts of the. percussive motor may still be used with either solid or hollow drill steels, to provide for an air connection to the fluid tube when the water connection is-detached, and in general to improve prior construction in the interests of economy both to the user and to the manufacturer.

In order to illustrate the invention, one embodiment thereof is shown in the accompanying drawings, in which Fig. 1 is a longitudinal sectional view of a drill embodying the invention arranged fo'rflwet operation; I

Fig. 2 is a view similar to Fig. 1 showing the same drill adapted for deep dry drills;

Fig. 3 is a view similar to Figs. 1 and 2 (with certain parts omitted) showing the same drill adapted for shallow dry drilling and stoping and indicating an air feed attached thereto for stoping work Figs. 4: and 5 are fragmentary detail views illustrating positions of the control or throttle valve.

The embodiment of the invention chosen for the purpose of illustration comprises a fluid pressure percussive drill of the hand type having a cylinder A provided with front and back heads B and C respectively and forming a piston chamber 1) within which reciprocates a piston E arranged to impart blows to a drill steel F suitably supported in the front head B. Proper provision is made for rotating the drill steel F during the drilling operation. In the einbodimentshown, rifle bar mechanism is utilized for this purpose comprising a rifle bar G rotatively supported in bearings in the back head C and cylinder ring H and held against rotation in one direction by oawls on the bar engaging a ratchet ring in the back head. A spirally fluted or ribbed portion of the rifle bar which extends into the piston chamber cooperates with a rifle nut J secured in a socket in the upper end of the piston E and the forward end of the piston has flutes or ribs engaging a similarly fluted sleeve K rotatively mount ed in the front. head and keyed to the drill steel chuck L. To provide for the clearing of the drill hole, the piston and rifle bar have the usual bore for the tube M, the head of which has a collar N with oppositely inclined bevelled surfaces engaged by hearing surfaces in the back head and clamping plug 0. Plug 0 may be locked in place by cap nut P.

The reciprocations of the piston E are controlled in the usual manner by an automatically operated valve (not'shown) supplied with motive fluid through the passage Q controlled by a throttle valve R which may be of the hollow plug type. The throttle valve R also controls a passage S through the back head which connects with ports in plug O to supply fluid to the tube M. This passage S is intersected by a bore T in the backhead. When the drill is used for wet drilling, a water connection plug U is provided for the bore '1 of suflicient length to interrupt and close ofl the air supply from the throttle valve R in the passage S,as clearly indicated in Fig. 1.

If it is desired to sendmotive fluid directly through the tube M instead of water, the water connection U of Fig. 1 is removed and a shorter plug U (Fig. 2) is substituted, which does not extend far enough into bore T to interrupt air passage S. In deep drilling, a continuous blast of motive fluid at full line pressure is necessary to keep the hole clear especially since the hole in the drill steel is small and of uncertain shape and induces friction. Under these conditions a hollow tube M (Fig. 2) with a larger bore is substituted for the water tube M and the throttle valve R is adjusted to supply motive fluid to passage S and tube l in any desired. amount.

If the drill is to be used for shallow holes or in stoping where the cuttings will toa large extent fall out of the drill hole, a short solid rod M 3) may be substituted for either the water tube M or the air tube l This rod M has a bevelled end which terminates adjacent the end of the rifle bar socketin piston E when the latter is at the limit of its outward movement (Fig. 3), thus providing an auxiliary exl'iaust for the piston chamber and directing intermittently through the hollow steel a blast of air which in shallow holes and in stoping insures a clean face before each han'imer blow at the bottom of the hole. It is to be understood that the main exhaust port- (not shown) connnunicates with the enhaust groove shown in the drawing substantially centrally of the piston chamber. TllS form of rod also permits the operator to use his drill without change with solid drill steels if desired or necessary.

The drill is further adapted and intended to be used with an air feed in stoping. Such an arrangen'ient is also illustrated in Fig. 3 wherein an air teed cylinder V together with its plunger rod and piston W may be clamped against the back head C in any suitable or desired manner. For this purpose the side bolts (not shown) used in drills of this kind to maintain the parts of the same in assembled relation, may be utilized, the same engaging ears (not shown) on the cylinder VJ To permit access oi the motive fluid to the air teed piston W, a plug U having a bore U therethrough may be provided for the bore T or the bore T may be left entirely open.

The valve R forms a single control element readily manipulated by the operator through a convenient handle (not shown) for selectively regulating the supply of motive fluid to passage Q leading to the percussive motor and to passage S leading. to the air tube or feed cylinder or both, individually or con comitantly. Fig. 4 illustrates valve R in position to shut oil the motive fluid from both passage Q and passage S. Fig. 3 illustrates the position of the valve when both passages are wide open to motive fluid. Fig. 1 illustrates the proper position of the valve when the tool is used as a wet drill, passage S being entirely closed; the force and speed of the percussive motor may now be reduced and regulated by turning the valve in a counter-clockwise direction. Fig. 2 illustrates the manner of selectively regulating the supply ort motive fluid to passage S while leaving the percussive motor in full operation, it being evident that slight movement of the valve in either direction will cut down or increase the supply out motor fluid to passage Swithout afl'ecting the supply to passage Q. Fig. 5 illustrates in general the position of the valve for controlling the speed and force of the porous sive motor while maintaining an unrestricted supply of fluid in passage S, it being evident that limited oscillations of the valve in either direction cut down or increase the supply to passage Q, without affecting the supply to passage S.

Inasmuch as the operation of the percussive motor of a drill of the kind illustrated is well known, detailed description thereof is omitted. The changing of the rods and tubes which fit the tube opening in the piston and permit the drill to operate either in a *wet or dry condition without other change, 1s obviously readily accomplished by removing cap nut P and plug 0.

From the above it will be apparent that this invention contemplates a form of percussive drill approximating the Universal type in that it is adapted and intended for use with no chan c or with ver 1 minor chan esin practically all of the operations and conditions under which the percussive type of drill can be used, and that it affords marked economies to the user who needs only a few inexpensive parts to adapt a single drill to all desired uses as well as economies to the manufacturer in permitting concentration of production upon a few types and a simplified stock of parts.

Having now described my invention and the manner of its use, what I claim and desire to secure by Letters Patent is:

1. A fluid pressure tool of the percussive type comprising a cylinder, a piston having an axial bore adapted to be reciprocated in said cylinder, a drill steel suitably mounted to receive the impact of said piston, an inter changeable member fitting the bore of said piston whereby the tool may be adapted for use with either solid or hollow drill steels, means providing for the removal or insertion of the interchangeable member without disassembling said tool, a fluid connection leading to the end of said member and a single valve for selectively controlling and regulating the supply of fluid to the piston and to said member.

.2. A fluid pressure tool of the percussive type comprising cylinder, a piston having an axial bore adapted to be reciprocated in said cylinder, a drill steel suitably mounted to receive the impact of said piston, a cylindrical tube fitting the bore of said piston, a fluid connection leading to the end oi said tube, interchangeable fltt-ings adapted to be associated with said connection whereby either water or motive fluid may be supplied to said tube, and a single valve for selectively controlling and regulating the supply of motive fluid admitted to said connection and for the actuation of said piston.

3. A fluid pressure tool of the percussive type comprising a cylinder, :1- piston having an axial bore adapted to be reciprocated in said cylinder, a drill steel suitably mounted to receive the impact of said piston, a tubular member fitting the bore of said piston, a backhead for said cylinder in which said member is removably mounted, a passage in said backhead connecting the end of said member to the motive fluid supply, said backhead having a bore intersecting said passage, and a water supply connection fitting said last-named bore for cutting ofl the flow of motive fluid in said passage when water is to be supplied to said member.

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4. A backhead for rock drills of the type having a piston reciprocable by pressure fluid and a cylindrical member disposed in an axial bore in said piston said backhead having said cylindrical member mounted therein for convenient removal and having a fluid passage extending to said member from the fluid pressure supply and interchangeable means disposed in a bore intersecting said passage for shutting off the pressure fluid connection and substituting a different connection, or for conducting motive fluid to an air feed cylinder secured to said head.

5. A backhead for rock drills of the type having a piston reciprocable by pressure fluid and a cylindrical member disposed in an axial bore in said piston, said backhead having said cylindrical member mounted therein for con venient removal and having a throttle valve for controlling the motive fluid supply to the drill, a passage under control of said valve eX- tending from the latter to said cylindrical member and means whereby a portion of said passage may be utilized for conducting fluid from a different source to said member or a different portion of said passage may be utilized to conduct motive fluid to a feed cylinder clamped against said backhead.

Signed by me at Detroit this 24th day of January, 1924. v

ERNEST PENBERTHY. 

